I told people... Commanders aren't that strong. Said it 400x fucking times.
For Katakuri to be made a proper challenge for Luffy, he had to turn into a Luffy-clone with CoC, and was made a "legend", even when compared to Smoothie/Cracker/Snack. That's why Oda gave Luffy 5th Emperor right after surpassing Katakuri. It's clear as fuck Katakuri > King.